Cutting device

Abstract

To provide a cutting device which can prevent the occurrence of a processing failure due to erroneous attachment of a cutting blade.SOLUTION: A cutting device for cutting a workpiece comprises: a chuck table which holds the workpiece on a holding surface; a cutting unit which includes a spindle in which a cutting blade for cutting the workpiece held on the holding surface is attached to the tip part; an imaging unit which images the outer peripheral part of the cutting blade attached to the cutting unit; and a determination unit which determines the orientation of the cutting blade. A plurality of protrusions including a first surface that feeds cutting chips generated when cutting the workpiece by the cutting blade and a second surface that is connected to the first surface are provided on the outer peripheral part of the cutting blade. The determination unit determines the orientation of the cutting blade attached to the cutting unit on the basis of an image of the protrusions acquired by the imaging unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cutting device for cutting a workpiece. [Background technology]

[0002] A wafer on which a plurality of devices are formed is divided and singulated to produce a plurality of device chips, each including a device. Furthermore, a package substrate is obtained by mounting a plurality of device chips on a base substrate and covering the mounted device chips with a resin sealing material (mold resin). A plurality of packaged devices, each including a plurality of packaged device chips, is produced by dividing and singulating this package substrate. The device chips and packaged devices are incorporated into various electronic devices, such as mobile phones and personal computers.

[0003] Cutting machines are used to divide workpieces such as wafers and package substrates. Cutting machines are equipped with a chuck table that holds the workpiece and a cutting unit that performs cutting on the workpiece. The cutting unit has a built-in spindle, and an annular cutting blade is attached to the tip of the spindle. The workpiece is held by the chuck table, and when the chuck table and cutting unit are moved relative to each other while the cutting blade is rotated (processing feed), the cutting blade cuts into the workpiece, cutting and dividing it.

[0004] The structure, material, etc. of the cutting blade are appropriately selected depending on the material, properties, etc. of the workpiece to be cut. For example, when cutting and dividing a plate-like object made of raw ceramics, a cutting blade having a plurality of saw-tooth-shaped protrusions on the outer periphery is sometimes used (see Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 4-179505 Summary of the Invention [Problem to be solved by the invention]

[0006] When cutting a workpiece with a cutting blade having a saw-tooth protrusion, the cutting blade is attached to the cutting unit in a predetermined orientation. Specifically, the protrusion has a rake face and a flank face, and the cutting blade is fixed to the tip of the spindle so that the rake face is positioned forward of the flank face in the direction of rotation of the cutting blade.

[0007] However, when attaching a cutting blade to a cutting unit, an operator must visually determine the orientation of the minute protrusions and attach the cutting blade in a predetermined orientation while taking into consideration the feed direction during cutting, etc. Therefore, it is easy for the cutting blade to be attached incorrectly, and if cutting of the workpiece continues with the cutting blade attached in the incorrect orientation, the workpiece may not be cut as intended, and processing defects may occur.

[0008] Furthermore, a so-called dual-spindle type cutting machine, in which a pair of cutting blades are attached to a pair of cutting units so that they face each other, is sometimes used to cut workpieces. In a dual-spindle type cutting machine, the orientation of the cutting blades relative to the spindle differs between the pair of cutting units. This makes it easy for an operator to mistake the correct orientation of the cutting blade, making it more likely that the cutting blade will be attached incorrectly.

[0009] The present invention has been made in view of the above problem, and has an object to provide a cutting device that can prevent the occurrence of processing defects due to incorrect attachment of a cutting blade. [Means for solving the problem]

[0010] According to one aspect of the present invention, there is provided a cutting device for cutting a workpiece, comprising: a chuck table for holding the workpiece on a holding surface; a cutting unit having a spindle to the tip of which is attached a cutting blade for cutting the workpiece held on the holding surface; an imaging unit for imaging the outer periphery of the cutting blade attached to the cutting unit; and a determination unit for determining the orientation of the cutting blade, wherein the outer periphery of the cutting blade is provided with a plurality of protrusions including a first surface for sending out cutting chips generated when the cutting blade cuts the workpiece, and a second surface connected to the first surface, and the determination unit determines the orientation of the cutting blade attached to the cutting unit based on the image of the protrusions acquired by the imaging unit.

[0011] Preferably, the determination unit determines the orientation of the cutting blade based on the dimensions of the first and second surfaces of the protrusion imaged by the imaging unit. Also, preferably, the determination unit determines the orientation of the cutting blade based on the inclination of the first and second surfaces of the protrusion imaged by the imaging unit. Also, preferably, the determination unit determines the orientation of the cutting blade based on a result of comparing the image of the protrusion imaged by the imaging unit with a reference image. [Effects of the Invention]

[0012] The cutting device according to one aspect of the present invention can determine the orientation of the cutting blade attached to the cutting unit based on an image of the protrusion of the cutting blade captured by the imaging unit. This prevents the cutting of the workpiece from being continued while the cutting blade is attached in the wrong orientation, thereby preventing processing defects caused by the incorrect attachment of the cutting blade. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. [Figure 2] FIG. 2(A) is a front view showing a cutting blade, and FIG. 2(B) is a front view showing an enlarged outer periphery of the cutting blade. [Figure 3] FIG. 2 is an exploded perspective view showing the cutting unit. [Figure 4] FIG. 2 is a partial cross-sectional front view showing the imaging unit. [Figure 5] FIG. 5(A) is a side view showing the first cutting unit, and FIG. 5(B) is a side view showing the second cutting unit. [Figure 6] FIG. 2 is a block diagram showing a control unit. [Figure 7] FIG. 7(A) is an image diagram showing a captured image, and FIG. 7(B) is an image diagram showing a composite image. [Figure 8] Figure 8(A) is an image diagram showing a portion of a composite image to which cutting edge position detection processing is performed, Figure 8(B) is an image diagram showing a portion of a composite image to which detection range setting processing is performed, and Figure 8(C) is an image diagram showing a portion of a composite image to which extreme value identification processing is performed. [Figure 9] FIG. 10 is an image diagram showing a part of a composite image to which a dimension calculation process is performed. [Figure 10] FIG. 10(A) is an image diagram showing a composite image, FIG. 10(B) is an image diagram showing an edge-detected image, and FIG. 10(C) is an image diagram showing an edge-detected image to which straight line extraction processing has been applied. [Figure 11] Figure 11(A) is an image showing a reference image, Figure 11(B) is an image showing an image of the protrusion portion of the cutting blade in a correctly installed state, and Figure 11(C) is an image showing an image of the protrusion portion of the cutting blade in an incorrectly installed state. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment according to one aspect of the present invention will be described below with reference to the accompanying drawings. First, a configuration example of a cutting device according to this embodiment will be described. FIG. 1 is a perspective view showing a cutting device 2 that performs cutting on a workpiece 11. In FIG. 1, the X-axis direction (processing feed direction, first horizontal direction, front-rear direction) and the Y-axis direction (indexing feed direction, second horizontal direction, left-right direction) are perpendicular to each other. Furthermore, the Z-axis direction (vertical direction, up-down direction, height direction) is perpendicular to the X-axis direction and the Y-axis direction.

[0015] The cutting device 2 includes a rectangular parallelepiped base 4 that supports or houses each of the components that make up the cutting device 2. A rectangular opening 4a is provided at a corner on the front end side of the base 4. A cassette support table 6 that is raised and lowered by a lifting mechanism (not shown) is provided inside the opening 4a. A cassette 8 that can house multiple workpieces 11 that are to be machined by the cutting device 2 is placed on the cassette support table 6. In FIG. 1, the outline of the cassette 8 is indicated by a two-dot chain line.

[0016] For example, the workpiece 11 is a disk-shaped wafer made of a semiconductor material such as single crystal silicon, and has a front surface and a back surface that are generally parallel to each other. The workpiece 11 is divided into a plurality of rectangular regions by a plurality of streets (planned division lines) that are arranged in a grid pattern so as to intersect with each other. In addition, a plurality of devices are formed on the front surface side of the workpiece 11 in each of the plurality of regions divided by the streets. Examples of the devices include ICs (Integrated Circuits), LSIs (Large Scale Integration), LEDs (Light Emitting Diodes), MEMS (Micro Electro Mechanical Systems) devices, etc.

[0017] A tape (dicing tape) 13 is attached to the back side of the workpiece 11. For example, the tape 13 includes a circular film (substrate) with a diameter larger than that of the workpiece 11, and an adhesive (glue layer) on the substrate. For example, the substrate is made of a resin such as polyolefin, polyvinyl chloride, or polyethylene terephthalate, and the adhesive is made of an epoxy-based, acrylic-based, or rubber-based adhesive. The adhesive may also be an ultraviolet-curable resin that hardens when exposed to ultraviolet light.

[0018] The outer periphery of tape 13 is attached to an annular frame 15 made of metal or the like. A circular opening is provided in the center of frame 15, penetrating frame 15 in the thickness direction. The diameter of the opening in frame 15 is larger than the diameter of workpiece 11, and workpiece 11 is placed inside the opening of frame 15. When the center of tape 13 is attached to workpiece 11 and the outer periphery of tape 13 is attached to frame 15, workpiece 11 is supported by frame 15 via tape 13.

[0019] The workpiece 11 is housed in a cassette 8 while being supported by a frame 15, and is cut by the cutting device 2. For example, the workpiece 11 is cut along the streets by the cutting device 2 to divide it, thereby obtaining a plurality of device chips each containing a device.

[0020] However, there are no limitations on the type, material, shape, structure, size, etc. of the workpiece 11. For example, the workpiece 11 may be a substrate (wafer) made of a semiconductor other than silicon (GaAs, InP, GaN, SiC, etc.), glass, sapphire, ceramics, resin, metal, etc. Furthermore, there are no limitations on the type, number, shape, structure, size, arrangement, etc. of devices, and the workpiece 11 does not necessarily have to have any devices formed thereon.

[0021] Furthermore, the workpiece 11 may be a package substrate such as a CSP (Chip Size Package) substrate or a QFN (Quad Flat Non-leaded package) substrate. For example, a package substrate is formed by sealing a plurality of device chips mounted on a base substrate with a resin layer (mold resin). By dividing the package substrate into individual pieces, a plurality of packaged devices each including a plurality of packaged device chips are manufactured.

[0022] A rectangular opening 4b is provided on the side of the opening 4a, with its longitudinal direction aligned with the X-axis direction. A chuck table (holding table) 10 for holding a workpiece 11 is provided inside the opening 4b. The upper surface of the chuck table 10 is a flat surface that is roughly parallel to the horizontal plane (XY plane), and forms a holding surface 10a for holding the workpiece 11. The holding surface 10a is connected to a suction source (not shown), such as an ejector, via a flow path (not shown), a valve (not shown), and the like, provided inside the chuck table 10.

[0023] The chuck table 10 is provided with a movement mechanism 12 that moves the chuck table 10 along the X-axis direction. For example, the movement mechanism 12 is a ball screw type movement mechanism that includes an X-axis ball screw (not shown) arranged along the X-axis direction and an X-axis pulse motor (not shown) that rotates the X-axis ball screw.

[0024] The moving mechanism 12 also includes a flat table cover 14 that is provided to surround the chuck table 10. Furthermore, accordion-shaped dust-proof and drip-proof covers 16 that are extendable and contractible along the X-axis direction are provided in front and behind the table cover 14. The table cover 14 and the dust-proof and drip-proof covers 16 are installed so as to cover the components of the moving mechanism 12 (X-axis ball screw, X-axis pulse motor, etc.) that are arranged inside the opening 4b.

[0025] A rotation drive source (not shown), such as a motor, is connected to the chuck table 10 to rotate the chuck table 10 around a rotation axis that is generally parallel to the Z-axis direction. In addition, a plurality of clamps 18 are provided around the periphery of the chuck table 10 to grip and fix a frame 15 that supports the workpiece 11.

[0026] A transport mechanism (not shown) that transports the workpiece 11 between the cassette 8 and the chuck table 10 is provided near the openings 4a and 4b. The workpiece 11 is drawn out of the cassette 8 by the transport mechanism and transported to the chuck table 10. At this time, the workpiece 11 is placed on the holding surface 10a of the chuck table 10 via the tape 13. In addition, the frame 15 is gripped by a plurality of clamps 18. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 10a, the workpiece 11 is sucked and held by the chuck table 10 via the tape 13.

[0027] A cutting unit 20a (first cutting unit) and a cutting unit 20b (second cutting unit) that cut the workpiece 11 are provided above the chuck table 10. In addition, a gate-shaped support structure 22 that supports the cutting units 20a and 20b is disposed on the upper surface of the base 4 so as to straddle the opening 4b.

[0028] Movement mechanisms 24a and 24b are provided on both end portions on the front side of the support structure 22. The movement mechanism 24a is a ball screw type movement mechanism that moves the cutting unit 20a along the Y-axis direction and the Z-axis direction, and the movement mechanism 24b is a ball screw type movement mechanism that moves the cutting unit 20b along the Y-axis direction and the Z-axis direction. The movement mechanisms 24a and 24b are attached to a pair of Y-axis guide rails 26 that are arranged on the front side of the support structure 22 along the Y-axis direction.

[0029] The movement mechanism 24a includes a flat Y-axis moving plate 28a. The Y-axis moving plate 28a is slidably mounted on a pair of Y-axis guide rails 26. A nut portion (not shown) is provided on the back side (rear side) of the Y-axis moving plate 28a. A Y-axis ball screw 30a, which is disposed generally parallel to the Y-axis guide rails 26, is threadedly engaged with this nut portion. A Y-axis pulse motor 32 that rotates the Y-axis ball screw 30a is connected to an end of the Y-axis ball screw 30a. When the Y-axis pulse motor 32 rotates the Y-axis ball screw 30a, the Y-axis moving plate 28a moves in the Y-axis direction along the Y-axis guide rails 26.

[0030] A pair of Z-axis guide rails 34a are fixed along the Z-axis direction to the surface (front) side of the Y-axis moving plate 28a. A flat Z-axis moving plate 36a is slidably mounted on the pair of Z-axis guide rails 34a. A nut portion (not shown) is provided on the back side (rear side) of the Z-axis moving plate 36a. A Z-axis ball screw 38a, which is disposed generally parallel to the Z-axis guide rails 34a, is threadedly engaged with this nut portion. A Z-axis pulse motor 40a, which rotates the Z-axis ball screw 38a, is coupled to the end of the Z-axis ball screw 38a. When the Z-axis pulse motor 40a rotates the Z-axis ball screw 38a, the Z-axis moving plate 36a moves in the Z-axis direction along the Z-axis guide rails 34a.

[0031] Similarly, the movement mechanism 24b includes a flat Y-axis moving plate 28b. The Y-axis moving plate 28b is slidably mounted on the pair of Y-axis guide rails 26. A nut portion (not shown) is provided on the back side (rear side) of the Y-axis moving plate 28b. A Y-axis ball screw 30b, which is disposed generally parallel to the Y-axis guide rails 26, is threadedly engaged with this nut portion. A Y-axis pulse motor (not shown) that rotates the Y-axis ball screw 30b is coupled to an end of the Y-axis ball screw 30b. When the Y-axis pulse motor rotates the Y-axis ball screw 30b, the Y-axis moving plate 28b moves in the Y-axis direction along the Y-axis guide rails 26.

[0032] A pair of Z-axis guide rails 34b are fixed along the Z-axis direction to the surface (front) side of the Y-axis moving plate 28b. A flat Z-axis moving plate 36b is slidably mounted on the pair of Z-axis guide rails 34b. A nut portion (not shown) is provided on the back side (rear side) of the Z-axis moving plate 36b. A Z-axis ball screw 38b, which is disposed generally parallel to the Z-axis guide rails 34b, is threadedly engaged with this nut portion. A Z-axis pulse motor 40b, which rotates the Z-axis ball screw 38b, is coupled to an end of the Z-axis ball screw 38b. When the Z-axis pulse motor 40b rotates the Z-axis ball screw 38b, the Z-axis moving plate 36b moves in the Z-axis direction along the Z-axis guide rails 34b.

[0033] Cutting unit 20a is fixed to the lower part of Z-axis moving plate 36a, and cutting unit 20b is fixed to the lower part of Z-axis moving plate 36b. In addition, an imaging unit 42 that captures an image of a subject such as workpiece 11 held by chuck table 10 is provided adjacent to cutting units 20a and 20b.

[0034] The imaging unit 42 includes an imaging element such as a CCD (Charged-Coupled Devices) sensor or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor, and an optical system including optical elements such as an objective lens. The type of imaging unit 42 can be appropriately selected depending on the material of the workpiece 11, etc. For example, a visible light camera or an infrared camera is used as the imaging unit 42. The image acquired by the imaging unit 42 is used for aligning the workpiece 11 with the cutting units 20a and 20b, etc.

[0035] A circular opening 4c is provided on the side of opening 4b. A cleaning unit 44 for cleaning workpiece 11 is provided inside opening 4c. Cleaning unit 44 includes a spinner table 46 that holds and rotates workpiece 11, and a nozzle 48 that supplies cleaning fluid to workpiece 11 held by spinner table 46.

[0036] The upper surface of the spinner table 46 is a flat surface that is roughly parallel to the horizontal plane (XY plane) and constitutes a holding surface 46a that holds the workpiece 11. The holding surface 46a is connected to a suction source (not shown) such as an ejector via a flow path (not shown), a valve (not shown), and the like that are provided inside the spinner table 46. In addition, the spinner table 46 is connected to a rotation drive source (not shown) such as a motor that rotates the spinner table 46 around a rotation axis that is roughly parallel to the Z-axis direction.

[0037] Nozzle 48 for supplying a cleaning fluid is disposed above spinner table 46. For example, a liquid (such as pure water) or a mixed fluid containing a liquid (such as pure water) and a gas (such as air) is used as the cleaning fluid. With workpiece 11 held by spinner table 46, the spinner table 46 is rotated while supplying the cleaning fluid from nozzle 48 toward workpiece 11, thereby cleaning workpiece 11.

[0038] A transfer mechanism (not shown) is provided near the openings 4b and 4c to transfer the workpiece 11 between the chuck table 10 and the spinner table 46. After the workpiece 11 is machined by the cutting units 20a and 20b, it is transferred from the chuck table 10 to the spinner table 46 by the transfer mechanism and cleaned. Then, the cleaned workpiece 11 is carried into the cassette 8 by the transfer mechanism.

[0039] A cover 50 is provided on the upper side of the base 4 to cover the components mounted on the base 4. In Fig. 1, the outline of the cover 50 is indicated by a two-dot chain line.

[0040] A display unit (display section, display device) 52 that displays information related to the cutting device 2 is provided on the side of the cover 50. The display unit 52 can be configured with various types of displays, and displays information related to the processing of the workpiece 11 (processing conditions, processing status, etc.). For example, a touch panel display is used as the display unit 52. In this case, the display unit 52 also functions as an input unit (input section, input device) for inputting information to the cutting device 2, and the operator can input information to the cutting device 2 by touching the display unit 52. In other words, the display unit 52 functions as a user interface.

[0041] An alarm unit (alarm section, alarm device) 54 that notifies the operator of information is provided on the top of the cover 50. For example, the alarm unit 54 is an indicator light (warning light), which lights up or flashes when an abnormality occurs in the cutting device 2 to notify the operator of the error. However, there is no limitation on the type of alarm unit 54. For example, the alarm unit 54 may be a speaker that notifies the operator of information by sound or voice.

[0042] The cutting device 2 also includes a control unit (controller, controller) 56 that controls the cutting device 2. The control unit 56 is connected to each of the components that make up the cutting device 2 (the cassette support base 6, the chuck table 10, the moving mechanism 12, the clamp 18, the cutting units 20a and 20b, the moving mechanisms 24a and 24b, the imaging unit 42, the cleaning unit 44, the display unit 52, the notification unit 54, etc.).

[0043] The control unit 56 outputs control signals to each component of the cutting device 2, thereby controlling the operation of each component and operating the cutting device 2. For example, the control unit 56 is configured by a computer, and includes a processor such as a CPU (Central Processing Unit) that performs calculations necessary for the operation of the cutting device 2, and memories such as a ROM (Read Only Memory) and RAM (Random Access Memory) that store various information (data, programs, etc.) used for operating the cutting device 2.

[0044] An annular cutting blade 58 for cutting the workpiece 11 is attached to each of the cutting units 20a and 20b. This positions the pair of cutting blades 58 facing each other. Each of the cutting units 20a and 20b cuts the workpiece 11 by rotating the cutting blade 58 and causing it to cut into the workpiece 11 held by suction on the chuck table 10. However, the number of cutting units provided in the cutting device 2 may be one.

[0045] 2(A) is a front view showing the cutting blade 58. For example, the cutting blade 58 is an annular cutting blade (metal saw, cemented carbide cutter) made of metal such as cemented carbide or stainless steel and containing no abrasive grains.

[0046] When the cutting blade 58 is a metal saw made of a cemented carbide, the metal contained in the cemented carbide can be selected appropriately. For example, the cutting blade 58 is made of a composite material (alloy) obtained by blending and sintering a carbide of a metal such as tungsten, chromium, molybdenum, titanium, zirconium, hafnium, vanadium, niobium, or tantalum with an iron-based metal (iron, cobalt, nickel, or the like). In particular, a WC-Co alloy containing tungsten carbide (WC) and cobalt exhibits high hardness over a wide temperature range and has excellent mechanical strength, making it a suitable material for the cutting blade 58.

[0047] However, there is no limitation on the material of the cutting blade 58. For example, the cutting blade 58 may be an annular grindstone formed by fixing abrasive grains made of diamond, cubic boron nitride (cBN), or the like with a binder made of metal, ceramics, resin, or the like.

[0048] A circular opening 58a is provided in the center of the cutting blade 58, penetrating the cutting blade 58 in the thickness direction. In addition, a plurality of saw-tooth-shaped protrusions (convex portions, saw blades) 60 are provided on the outer periphery of the cutting blade 58, protruding radially outward from the cutting blade 58. The plurality of protrusions 60 are formed in roughly the same shape and are arranged at roughly equal intervals along the circumferential direction of the cutting blade 58.

[0049] 2(B) is an enlarged front view showing the outer periphery of the cutting blade 58. The protrusion 60 includes a first surface (rake face) 60a and a second surface (flank face) 60b that are generally parallel to the thickness direction of the cutting blade 58. One end (tip) of the first surface 60a and one end (tip) of the second surface 60b are connected to each other and form a tip 60c of the protrusion 60. The other end (base end) of the first surface 60a and the other end (base end) of the second surface 60b each form a bottom (cutting bottom) 60d of the protrusion 60 and are connected to the bottom 60d of another adjacent protrusion 60.

[0050] The inclination angle of the first surface 60a with respect to the radial direction of the cutting blade 58 is smaller than the inclination angle of the second surface 60b with respect to the radial direction of the cutting blade 58. That is, the protrusion 60 is formed so that the first surface 60a is steeper than the second surface 60b. For example, the first surface 60a is formed parallel to the radial direction of the cutting blade 58 (inclination angle = 0°), and the second surface 60b is formed so as to be inclined with respect to the radial direction of the cutting blade 58 (inclination angle > 0°). Furthermore, the distance from one end to the other end of the first surface 60a is shorter than the distance from one end to the other end of the second surface 60b, and the area of the first surface 60a is smaller than the area of the second surface 60b.

[0051] The cutting blade 58 is attached to the cutting unit 20a (see FIG. 1) and rotates in the direction indicated by arrow A (see FIG. 2(A)). That is, the cutting blade 58 rotates so that the first surface 60a of each protrusion 60 is positioned forward of the second surface 60b in the direction of rotation of the cutting blade 58. The cutting unit 20a cuts the workpiece 11 held by the chuck table 10 with the rotating cutting blade 58. Similarly, the cutting blade 58 is attached to the cutting unit 20b (see FIG. 1), and the cutting unit 20b cuts the workpiece 11 with the cutting blade 58.

[0052] When the rotating cutting blade 58 is caused to cut into the workpiece 11, the first surface 60a of the protrusion 60 mainly comes into contact with the workpiece 11 and cuts away the workpiece 11. Then, chips (cutting chips) generated when the cutting blade 58 cuts the workpiece 11 are sent forward in the rotation direction of the cutting blade 58 by the first surface 60a.

[0053] Next, an example of the configuration of the cutting units 20a and 20b will be described. Note that, although an example of the configuration of the cutting unit 20a will be described below, the cutting unit 20b can also be configured in the same manner as the cutting unit 20a.

[0054] 3 is an exploded perspective view showing the cutting unit 20a. The cutting unit 20a includes a columnar housing 62 connected to the moving mechanism 24a (see FIG. 1). The housing 62 accommodates a cylindrical spindle 64 arranged along the Y-axis direction. The tip (one end) of the spindle 64 is exposed from the housing 62, and a rotation drive source (not shown), such as a motor, is connected to the base end (the other end) of the spindle 64. An opening 64a is provided at the tip of the spindle 64, and a thread groove 64b is provided on the inner wall of the opening 64a.

[0055] A blade mount 66 is fixed to the tip of the spindle 64. The blade mount 66 includes a disk-shaped flange 68 and a cylindrical boss (support shaft) 70 that protrudes from a surface 68a of the flange 68. The blade mount 66 also has an opening 66a that passes through the centers of the flange 68 and the boss 70. The blade mount 66 is fixed to the tip of the spindle 64 by inserting a fixing bolt 72 into the opening 64a of the spindle 64 through the opening 66a of the blade mount 66 and tightening it into the thread groove 64b.

[0056] An annular protrusion 68b protruding from the surface 68a of the outer periphery of the flange 68 is provided along the outer periphery of the flange 68. The tip surface of the protrusion 68b is a flat surface that is generally parallel to the surface 68a and forms a support surface that supports the cutting blade 58. A thread groove 70a is formed on the outer periphery of the boss 70.

[0057] The cutting blade 58 and an annular flange (pressing flange) 74 made of metal or the like are attached to the blade mount 66. A circular opening 74a is provided in the center of the flange 74, penetrating the flange 74 in the thickness direction.

[0058] When the boss portion 70 of the blade mount 66 is inserted into the opening 58a of the cutting blade 58 and the opening 74a of the flange 74, in that order, the cutting blade 58 and flange 74 are supported by the blade mount 66. In this state, when the annular fixing nut 76 is screwed into the thread groove 70a of the boss portion 70 and tightened, the cutting blade 58 and flange 74 are fixed to the blade mount 66. As a result, the cutting blade 58 is sandwiched between the flange portion 68 and the flange 74 and attached to the tip of the spindle 64.

[0059] Also attached to the housing 62 is a blade cover 78 that covers the cutting blade 58 attached to the tip (blade mount 66) of the spindle 64. The blade cover 78 includes a main body 80 fixed to the tip of the housing 62, and a slide cover 82 that is slidable along the X-axis direction so as to move toward and away from the main body 80.

[0060] The slide cover 82 is connected to the main body 80 via an air cylinder 84. When air is supplied to a connector 86 provided on the main body 80, the air cylinder 84 is driven, and the slide cover 82 slides along the X-axis direction away from the main body 80. This opens the blade cover 78, allowing the cutting blade 58 to be attached to the tip of the spindle 64. After the cutting blade 58 is attached, the slide cover 82 is slid toward the main body 80 to close the blade cover 78, thereby covering the cutting blade 58.

[0061] The main body 80 is provided with a connector 88 to which a liquid (cutting fluid) such as pure water is supplied, and a cutting fluid supply path (not shown) connected to the connector 88. The tip of the cutting fluid supply path opens toward the outer periphery of the cutting blade 58. When cutting fluid is supplied to the connector 88, the cutting fluid flows into the cutting fluid supply path and is supplied to the outer periphery of the cutting blade 58.

[0062] The slide cover 82 is provided with a pair of connectors 90 through which a liquid (cutting fluid) such as pure water is supplied, and a pair of nozzles 92 connected to the pair of connectors 90. The pair of nozzles 92 are arranged to sandwich the lower part of the cutting blade 58 attached to the tip of the spindle 64. The tip of the nozzle 92 is provided with a cutting fluid supply port (not shown) that opens toward the cutting blade 58. When cutting fluid is supplied to the pair of connectors 90, the cutting fluid flows into the pair of nozzles 92 and is sprayed from the cutting fluid supply port toward the front and back surfaces of the cutting blade 58.

[0063] The cutting blade 58 attached to the tip of the spindle 64 rotates around a rotation axis roughly parallel to the Y-axis direction by power transmitted from a rotation drive source (not shown) via the spindle 64 and the blade mount 66. The rotating cutting blade 58 cuts into the workpiece 11 (see FIG. 1), thereby cutting the workpiece 11. During cutting of the workpiece 11, cutting fluid is supplied to the workpiece 11 and the cutting blade 58. This cools the workpiece 11 and the cutting blade 58, and also washes away cutting chips generated by cutting the workpiece 11.

[0064] Furthermore, the blade cover 78 is provided with an imaging unit 94 that captures an image of the cutting blade 58. By capturing an image of the outer periphery of the cutting blade 58 attached to the cutting unit 20a with the imaging unit 94, the condition of the outer periphery of the cutting blade 58 can be monitored.

[0065] 4 is a partial cross-sectional front view showing the imaging unit 94. The imaging unit 94 includes a light-emitting unit 100 that emits light and a light-receiving unit 110 that receives the light emitted by the light-emitting unit 100. The light-emitting unit 100 and the light-receiving unit 110 are arranged to sandwich the upper end of the cutting blade 58 attached to the tip of the spindle 64 in the Y-axis direction.

[0066] The light-emitting unit 100 includes a rectangular parallelepiped housing 102. Housing 102 houses a light source 104 such as an LED, a condenser lens 106, and a mirror 108. Light emitted by light source 104 is incident on condenser lens 106 provided below light source 104. The light emitted from condenser lens 106 is then condensed and reflected by the surface of mirror 108 provided below condenser lens 106, and is then irradiated toward light-receiving unit 110. The light emitted from light-emitting unit 100 travels in a direction substantially parallel to the Y-axis direction and reaches light-receiving unit 110.

[0067] The light receiving unit 110 includes a microscope 112 that magnifies an image formed by light that has reached the light receiving unit 110 from the light emitting unit 100 , and a camera 122 that captures the image magnified by the microscope 112 .

[0068] The microscope 112 includes a rectangular parallelepiped housing 114. The housing 114 houses a mirror 116 and convex lenses 118 and 120. Light that reaches the light receiving unit 110 from the light emitting unit 100 is reflected by the surface of the mirror 116 and passes through the convex lenses 118 and 120 in that order. The light that is emitted from the convex lens 120 then enters the camera 122. The camera 122 includes an imaging element (such as a CCD sensor or a CMOS sensor) that converts the light that has entered from the microscope 112 into an electrical signal, and captures an image of the light that has entered from the microscope 112.

[0069] Further, the blade cover 78 is provided with a gas supply passage 124. One end of the gas supply passage 124 opens toward the upper end of the cutting blade 58, and the other end of the gas supply passage 124 is connected to a gas supply source 126. Gas such as air supplied from the gas supply source 126 to the gas supply passage 124 is sprayed from the gas supply passage 124 onto the upper end of the cutting blade 58. This removes foreign matter (cutting chips, cutting fluid, etc.) adhering to the cutting blade 58.

[0070] When the light source 104 is turned on with the cutting blade 58 attached to the tip of the spindle 64, light is emitted from the light-emitting unit 100 toward the light-receiving unit 110. At this time, part of the light emitted from the light-emitting unit 100 is blocked by the outer periphery (upper end) of the cutting blade 58 and does not reach the light-receiving unit 110. When the light that reaches the light-receiving unit 110 and passes through the microscope 112 is captured by the camera 122, an enlarged image of the outer periphery of the cutting blade 58 is obtained.

[0071] For example, the imaging unit 94 images the outer periphery of the cutting blade 58 before, during, or after processing the workpiece 11. This allows the amount of wear on the cutting blade 58, the presence or absence of chips or cracks on the outer periphery of the cutting blade 58, and the like to be confirmed, thereby monitoring the condition of the cutting blade 58. Note that, before imaging the cutting blade 58, gas may be sprayed onto the cutting blade 58 from the gas supply path 124 to remove any foreign matter adhering to the cutting blade 58, thereby preventing the foreign matter from appearing in the image of the cutting blade 58 acquired by the imaging unit 94.

[0072] Fig. 5(A) is a side view showing cutting unit 20a, and Fig. 5(B) is a side view showing cutting unit 20b. A cutting blade 58 is attached to each of cutting units 20a and 20b, and the pair of cutting blades 58 are arranged to face each other (see Fig. 1). In addition, an imaging unit 94 is attached to each of cutting units 20a and 20b, and the outer peripheries (upper ends) of the pair of cutting blades 58 are imaged by the imaging unit 94.

[0073] When viewing the cutting blade 58 from the side of the fixing nut 76, the rotation directions of the cutting blade 58 and the spindle 64 are opposite between the cutting unit 20a and the cutting unit 20b. For example, the cutting blade 58 attached to the cutting unit 20a rotates clockwise (the direction indicated by arrow A in FIG. 5(A)), and the cutting blade 58 attached to the cutting unit 20b rotates counterclockwise (the direction indicated by arrow B in FIG. 5(B)).

[0074] As described above, the cutting blade 58 is attached to the cutting units 20a and 20b so that the first surface 60a of each protrusion 60 is positioned forward of the second surface 60b in the rotation direction of the cutting blade 58. Therefore, as shown in Figures 5(A) and 5(B), the attachment direction of the cutting blade 58 (the direction of the protrusion 60) is opposite between the cutting unit 20a and the cutting unit 20b.

[0075] However, when attaching the cutting blade 58 to the cutting units 20a and 20b, the operator must visually determine the orientation of the minute protrusions 60 and attach the cutting blade 58 in a predetermined orientation while taking into consideration the cutting feed direction and other factors. Therefore, incorrect attachment of the cutting blade 58, i.e., incorrect attachment, is likely to occur. In particular, when a pair of cutting blades 58 are attached to the cutting units 20a and 20b in different orientations as shown in FIGS. 5(A) and 5(B), the operator is likely to confuse the correct orientation of the cutting blade 58, making incorrect attachment of the cutting blade 58 more likely. Furthermore, if cutting of the workpiece 11 continues while the cutting blade 58 is attached in the incorrect orientation, the workpiece 11 may not be cut as intended, resulting in processing defects.

[0076] Therefore, in this embodiment, the imaging unit 94 captures an image of the outer periphery of the cutting blade 58 attached to the cutting units 20a and 20b, and the orientation of the cutting blade 58 is determined based on the image of the cutting blade 58 acquired by the imaging unit 94. This prevents cutting of the workpiece 11 from being continued while the cutting blade 58 is attached in the wrong orientation.

[0077] The determination of the orientation of the cutting blade 58 is controlled by the control unit 56 (see FIG. 1) of the cutting device 2. FIG. 6 is a block diagram showing the control unit 56. Note that FIG. 6 also shows some of the components of the cutting device 2 (cutting unit 20a, display unit 52, notification unit 54, and imaging unit 94) in addition to a block showing the functional configuration of the control unit 56. Furthermore, although the determination of the orientation of the cutting blade 58 attached to the cutting unit 20a will be described below, the determination of the orientation of the cutting blade 58 attached to the cutting unit 20b can also be performed by a similar process.

[0078] The control unit 56 includes a processing unit 130 that executes processes necessary for the operation of the cutting device 2, and a storage unit 136 that stores information (data, programs, etc.) used for processing by the processing unit 130. The processing unit 130 also includes a determination unit 132 that determines the orientation of the cutting blade 58 attached to the cutting unit 20a, and a drive control unit 134 that controls the drive of the components of the cutting device 2 based on the result of the determination by the determination unit 132.

[0079] The determination unit 132 is connected to the camera 122 provided in the imaging unit 94. The determination unit 132 also includes an image acquisition unit 132a that acquires an image of the outer periphery (upper end) of the cutting blade 58. The imaging unit 94 captures an image of the outer periphery of the cutting blade 58 attached to the cutting unit 20a. Then, the image (captured image) of the outer periphery of the cutting blade 58 acquired by the imaging unit 94 is input to the image acquisition unit 132a.

[0080] 7(A) is an image diagram showing the captured image 140. The captured image 140 includes an image corresponding to the protrusion 60 of the cutting blade 58. The left-right direction of the captured image 140 corresponds to the X-axis direction, and the up-down direction of the captured image 140 corresponds to the Z-axis direction. When the captured image 140 is input from the imaging unit 94 to the image acquisition section 132a, the image acquisition section 132a stores the captured image 140 in the memory section 136.

[0081] Note that multiple captured images 140 may be obtained by capturing images of the outer periphery of the cutting blade 58 multiple times with the imaging unit 94 while the cutting blade 58 is being rotated. For example, the imaging unit 94 continuously captures images of the outer periphery of the cutting blade 58 until the cutting blade 58 makes one rotation. In this case, captured images 140 of the entire outer periphery of the cutting blade 58 are captured.

[0082] 7(B) is an image diagram showing the composite image 142. When a plurality of captured images 140 are captured by the imaging unit 94, the image acquisition unit 132a may generate a composite image 142 showing the entire outer periphery of the cutting blade 58 by connecting and combining the plurality of captured images 140. The composite image 142 includes images of the plurality of protrusions 60. The image acquisition unit 132a then stores the composite image 142 in the storage unit 136.

[0083] The determination unit 132 also includes an image processing unit 132b that performs image processing on the captured image 140 or the composite image 142. The image processing unit 132b performs image processing on the captured image 140 or the composite image 142 stored in the storage unit 136, thereby extracting information necessary for determining the orientation of the cutting blade 58 attached to the cutting unit 20a from the captured image 140 or the composite image 142. Specific examples of image processing by the image processing unit 132b will be described later.

[0084] Furthermore, the determination unit 132 includes an orientation determination unit 132c that determines the orientation of the cutting blade 58 based on the results of image processing. The orientation determination unit 132c determines whether the cutting blade 58 is in a properly attached state or an incorrectly attached state based on the information output from the image processing unit 132b. The properly attached state corresponds to a state in which the cutting blade 58 is attached so that the first surface 60a of the protrusion 60 is positioned forward of the second surface 60b in the direction of rotation of the cutting blade 58 (see FIGS. 5(A) and 5(B)). On the other hand, the incorrectly attached state corresponds to a state in which the cutting blade 58 is attached so that the first surface 60a of the protrusion 60 is positioned backward of the second surface 60b in the direction of rotation of the cutting blade 58.

[0085] Furthermore, the orientation determination unit 132c outputs a signal indicating that the cutting blade 58 is in a properly attached state (proper attachment signal) or a signal indicating that the cutting blade 58 is in an incorrectly attached state (incorrect attachment signal) as a determination result to the drive control unit 134. Then, the drive control unit 134 controls the operation of each component of the cutting device 2 based on the determination result of the determination unit 132.

[0086] Specifically, when a correct mounting signal is input from the orientation determination unit 132c to the drive control unit 134, the drive control unit 134 outputs a control signal to each component of the cutting device 2, causing the cutting device 2 to cut the workpiece 11 with the cutting blade 58. As a result, the workpiece 11 is cut by the cutting blade 58 that is mounted in the correct orientation.

[0087] On the other hand, when an incorrect attachment signal is input from the orientation determination unit 132c to the drive control unit 134, the drive control unit 134 outputs a control signal to each component of the cutting device 2, causing the cutting device 2 to temporarily stop cutting the workpiece 11. The drive control unit 134 also outputs a control signal to the display unit 52 and the alarm unit 54, causing them to issue a warning to notify the operator that the cutting blade 58 is attached in the wrong orientation. For example, the drive control unit 134 causes the display unit 52 to display a message notifying the operator that the cutting blade 58 is attached in the wrong orientation, and causes the alarm unit 54 (indicator light) to light up or flash.

[0088] Next, a cutting blade determination method for determining the mounting orientation of the cutting blade 58 using the above-described cutting device 2 will be described with reference to Figures 6 to 9. Note that, as an example, the following will describe in detail a case where the determination unit 132 determines the orientation of the cutting blade 58 based on the dimensions of the first surface 60a and the second surface 60b (see Figure 2(B)) of the protrusion 60.

[0089] First, an imaging process is executed in which the imaging unit 94 captures an image of the outer periphery of the cutting blade 58 and acquires a captured image 140 (see FIG. 7(A)). For example, the cutting blade 58 is rotated while the imaging unit 94 captures an image of the outer periphery of the cutting blade 58 multiple times, thereby acquiring multiple captured images 140. The multiple captured images 140 acquired by the imaging unit 94 are input to the image acquisition section 132a. Then, the image acquisition section 132a generates a composite image 142 (see FIG. 7(B)) including images of the multiple protrusions 60 by combining the multiple captured images 140, and stores the composite image 142 in the memory section 136.

[0090] Next, the image processing unit 132b executes cutting edge position detection processing to detect the position of the tip (cutting edge) of the cutting blade 58. Fig. 8(A) is an image diagram showing a part of the composite image 142 to which cutting edge position detection processing is applied.

[0091] In the cutting edge position detection process, first, the composite image 142 stored in the storage unit 136 is read by the image processing unit 132b, and the image processing unit 132b performs binarization processing on the composite image 142. This makes it easier to distinguish the outline of the cutting blade 58 shown in the composite image 142. However, if the contrast of the composite image 142 is sufficiently high, the binarization processing may be omitted.

[0092] Next, the image processing unit 132b detects the gradation of the pixels in the leftmost row of the composite image 142 (pixels in the first row) in order from top to bottom (in the -Z direction) and determines whether each pixel is displayed in white or black. The image processing unit 132b then records the coordinates of the point at which the pixel display changes from white to black as the coordinates of the tip of the cutting blade 58. Thereafter, the same process is repeated for pixels in the second row and thereafter. As a result, a set of coordinates indicating the tip position of the cutting blade 58 is obtained.

[0093] Next, the image processing unit 132b executes a detection range setting process to set a range in the composite image 142 for detecting the dimensions of the cutting blade 58. Fig. 8(B) is an image diagram showing a part of the composite image 142 to which the detection range setting process is applied.

[0094] For example, the image processing unit 132b refers to the coordinates of the tip position of the cutting blade 58 acquired by the cutting edge position detection process, and calculates the minimum value Z of the Z coordinate. min and the maximum value Z max Then, the image processing unit 132b identifies the Z coordinate of the composite image 142 as Z min More than Z max The following range is set as the detection range used to detect the dimensions of the cutting blade 58. This detection range includes images of the multiple protrusions 60.

[0095] Furthermore, the image processing unit 132b sets a threshold value to be used in the extreme value identification process described later. For example, the image processing unit 132b sets Z min and Z max and the average value Z ave Calculate Z min and Z ave A predetermined value between the first threshold Z th1 , Z max and Z ave A predetermined value between the second threshold Z th2 Set to.

[0096] Next, the image processing unit 132b executes an extreme value identification process to identify the maximum and minimum values of the coordinates of the tip position of the cutting blade 58. Fig. 8(C) is an image diagram showing a part of the composite image 142 to which the extreme value identification process is applied.

[0097] For example, the image processing unit 132b reads the Z coordinate of the tip position of the cutting blade 58 in order from the left end to the right end (-X direction) of the composite image 142. At this time, the image processing unit 132b reads the Z coordinate of the tip position of the cutting blade 58 while switching between a mode for detecting a maximum value of the Z coordinate (maximum value detection mode) and a mode for detecting a minimum value of the Z coordinate (minimum value detection mode).

[0098] Specifically, first, the image processing unit 132b sequentially reads the Z coordinate of the tip position of the cutting blade 58 in the -X direction in the maximum value detection mode. Then, when the Z coordinate of the tip position of the cutting blade 58 is equal to or smaller than the first threshold value Z th1 When this occurs, the system switches from maximum value detection mode to minimum value detection mode, and the image processor 132b identifies the maximum Z coordinate value read while the system was in the maximum value detection mode. The coordinates of the point where this maximum value is obtained (maximum point 142a) are recorded as the coordinates of the tip 60c of the protrusion 60 of the cutting blade 58 (see FIG. 2(B)).

[0099] Next, the image processing unit 132b sequentially reads the Z coordinate of the tip position of the cutting blade 58 along the -X direction in the minimum value detection mode. th2When this occurs, the system switches from the minimum value detection mode to the maximum value detection mode, and the image processor 132b identifies the minimum value of the Z coordinates read while the system was in the minimum value detection mode. The coordinates of the point where this minimum value is obtained (minimum point 142b) are recorded as the coordinates of the bottom 60d of the protrusion 60 of the cutting blade 58 (see FIG. 2(B)).

[0100] By repeating the above process, the coordinates of a plurality of local maximum points 142a and a plurality of local minimum points 142b included in the composite image 142 are identified. Note that in the above, a binary threshold (Z th1 ,Z th2 ) is used in the above description, but the threshold value may be a single value. For example, if the threshold value is Z ave (See FIG. 8(B)) can also be used.

[0101] However, when a plurality of captured images 140 (see FIG. 7A) are combined to generate a composite image 142, the image of the cutting blade 58 becomes discontinuous at the joints of the captured images 140, and minute steps that do not exist on the actual cutting blade 58 may appear in the composite image 142. ave When the Z coordinate of the step overlaps with the threshold value, the step may erroneously switch from the maximum value detection mode to the minimum value detection mode and vice versa, resulting in the upper and lower ends of the step being erroneously detected as the maximum point 142a and the minimum point 142b. th1 ,Z th2 ) and set the above step part to Z th1 ,Z th2 Z th1 ,Z th2 By adjusting the difference between the values, it is possible to avoid erroneous detection of extreme values at stepped portions.

[0102] Next, the image processing unit 132b executes a dimension calculation process to calculate the dimensions of the first surface 60a and the second surface 60b (see FIG. 2(B)) of the protrusion 60 based on the coordinates of the maximum point 142a and the minimum point 142b. For example, the image processing unit 132b calculates a value corresponding to the distance between the tip 60c and the bottom 60d (see FIG. 2(B)) of the protrusion 60 of the cutting blade 58. FIG. 9 is an image diagram showing a part of the composite image 142 to which the dimension calculation process is applied.

[0103] First, the image processing unit 132b calculates the distance D1 in the X-axis direction between a given maximum point 142a and the minimum point 142b adjacent to the right of the maximum point 142a. Next, the image processing unit 132b calculates the distance D2 in the X-axis direction between the minimum point 142b used in calculating the distance D1 and the maximum point 142a adjacent to the right of the minimum point 142b. Furthermore, the image processing unit 132b calculates the distance D1 in the X-axis direction between the maximum point 142a used in calculating the distance D2 and the minimum point 142b adjacent to the right of the maximum point 142a.

[0104] By performing the above process on all of the maximum points 142a and minimum points 142b, multiple distances D1 and D2 are calculated. Then, the image processing unit 132b calculates the average value of D1 and the average value of D2, and outputs them to the orientation determination unit 132c. Note that the image processing unit 132b may also output the total value of D1 and the total value of D2 to the orientation determination unit 132c.

[0105] Next, the orientation determination unit 132c executes an orientation determination process to determine the orientation of the cutting blade 58 attached to the cutting unit 20a based on the value input from the image processing unit 132b. For example, the orientation determination unit 132c compares the average value (or total value) of D1 with the average value (or total value) of D2, and determines the orientation of the cutting blade 58 based on the magnitude relationship between the two.

[0106] Specifically, when the cutting blade 58 is attached to the cutting unit 20a so that the first surface 60a of the protrusion 60 is positioned forward of the second surface 60b in the rotation direction of the cutting blade 58 (see FIG. 5(A)), a composite image 142 such as that shown in FIG. 9 is obtained. The average value of D1, which corresponds to the distance from the maximum point 142a to the minimum point 142b, is smaller than the average value of D2, which corresponds to the distance from the minimum point 142b to the maximum point 142a. In this case, the orientation determination unit 132c determines that the cutting blade 58 is attached in the correct orientation (properly attached state), and outputs a proper attachment signal to the drive control unit 134.

[0107] On the other hand, if the cutting blade 58 is mistakenly attached to the cutting unit 20a so that the first surface 60a of the protrusion 60 is positioned further rearward in the rotation direction of the cutting blade 58 than the second surface 60b, a composite image similar to the composite image 142 shown in FIG. 9 is obtained by flipping it horizontally. The average value of D1, which corresponds to the distance from the maximum point 142a to the minimum point 142b, will be greater than the average value of D2, which corresponds to the distance from the minimum point 142b to the maximum point 142a. In this case, the orientation determination unit 132c determines that the cutting blade 58 is attached in the wrong orientation (mis-attached state) and outputs an incorrect attachment signal to the drive control unit 134.

[0108] For example, the storage unit 136 stores in advance reference information indicating the relationship between the dimensions of the protrusion 60 and the state (properly attached state or incorrectly attached state) of the cutting blade 58. Then, the orientation determination unit 132c determines whether the cutting blade 58 is in a properly attached state or an incorrectly attached state based on the dimension values and the reference information input from the image processing unit 132b.

[0109] As described above, the image processing unit 132b calculates values corresponding to the dimensions of the protrusions 60 of the cutting blade 58 imaged by the imaging unit 94. Then, the orientation determination unit 132c determines the orientation of the cutting blade 58 based on the dimension values calculated by the image processing unit 132b.

[0110] Note that the values calculated by the image processing unit 132b are not limited to the average value (or total value) of the distances D1 and the average value (or total value) of the distances D2. For example, the image processing unit 132b may calculate the straight-line distance from the maximum point 142a to the minimum point 142b and the straight-line distance from the minimum point 142b to the maximum point 142a, and output them to the orientation determination unit 132c.

[0111] The determination by the determination unit 132 is realized by executing a program stored in the storage unit 136 (memory). Specifically, the storage unit 136 stores a program that describes each process to be executed by the imaging unit 94 and the determination unit 132. The control unit 56 then reads out and executes the program from the storage unit 136, thereby automatically determining the orientation of the cutting blade 58.

[0112] As described above, the cutting device according to this embodiment can determine the orientation of the cutting blade 58 attached to the cutting unit 20a based on the image of the protrusion 60 of the cutting blade 58 acquired by the imaging unit 94. This makes it possible to avoid continuing to cut the workpiece 11 with the cutting blade 58 attached in the wrong orientation, thereby preventing the occurrence of processing defects due to the incorrect attachment of the cutting blade 58.

[0113] In the above embodiment, an example has been described in which the determination unit 132 determines the orientation of the cutting blade 58 based on the dimensions of the protrusion 60 of the cutting blade 58. However, the method of determining the orientation of the cutting blade 58 is not limited to this. For example, the determination unit 132 can also determine the orientation of the cutting blade 58 based on the inclination of the first surface 60a and the second surface 60b of the protrusion 60. Hereinafter, other examples of the method of determining the orientation of the cutting blade will be described with reference to Fig. 6 and Figs. 10(A) to 10(C).

[0114] First, according to the procedure described above, the imaging unit 94 continuously captures images of the outer periphery of the cutting blade 58 to obtain multiple captured images. Then, the image acquisition unit 132a combines the multiple captured images to generate a composite image and stores the composite image in the storage unit 136.

[0115] Fig. 10(A) is an image diagram showing a composite image 152 generated by combining a plurality of captured images 150. Fig. 10(A) illustrates the composite image 152 in the case where the first surface 60a and the second surface 60b of the protrusion 60 of the cutting blade 58 are substantially linear in front view.

[0116] Next, the image processing unit 132b reads out the composite image 152 stored in the storage unit 136, and performs binarization processing on the composite image 152. However, if the contrast of the composite image 152 is sufficiently high, the binarization processing may be omitted.

[0117] Next, the image processing unit 132b performs edge detection processing on the composite image 152 to detect edges, thereby detecting the tip (cutting edge) of the cutting blade 58. For example, when the edge detection processing is performed on the composite image 152, an edge-detected image is generated in which points where the display of pixels in the composite image 152 switches from white to black are displayed in white, and other areas of the composite image 152 are displayed in black.

[0118] 10(B) is an image diagram showing the edge-detected image 154. The edge-detected image 154 displays an edge line 154a that represents the edge included in the composite image 152. The edge line 154a corresponds to the shape of the tip of the cutting blade 58.

[0119] Next, the image processing unit 132b performs a line extraction process to extract line components included in the edge line 154a by performing image processing on the edge-detected image 154. Fig. 10(C) is an image diagram showing the edge-detected image 154 to which the line extraction process has been performed.

[0120] The edge line 154a includes a plurality of first straight line 156a components corresponding to the first surface 60a (see FIG. 2(B)) of the cutting blade 58 and a plurality of second straight line 156b components corresponding to the second surface 60b (see FIG. 2(B)) of the cutting blade 58. The inclination angle of the first straight line 156a with respect to the Z-axis direction is smaller than the inclination angle of the second straight line 156b with respect to the Z-axis direction. In other words, the first straight line 156a and the second straight line 156b can be distinguished based on the angle (inclination angle).

[0121] The image processing unit 132b extracts a plurality of straight lines included in the edge line 154a by performing a straight line extraction process on the edge-detected image 154. The image processing unit 132b also identifies the angles of the extracted plurality of straight lines and classifies the plurality of straight lines into first straight lines 156a and second straight lines 156b.

[0122] For example, the image processing unit 132b performs a Hough transform on the edge-detected image 154. As a result, multiple straight lines included in the edge line 154a are extracted and the angles of each straight line are identified. The image processing unit 132b also classifies the multiple straight lines into first straight lines 156a and second straight lines 156b by comparing the angles of the extracted straight lines with a preset threshold. Then, for example, the image processing unit 132b outputs the average angle of the first straight lines 156a and the average angle of the second straight lines 156b to the orientation determination unit 132c.

[0123] The orientation determination unit 132c executes an orientation determination process to determine the orientation of the cutting blade 58 attached to the cutting unit 20a based on the value input from the image processing unit 132b (the angle between the first line 156a and the second line 156b). For example, the orientation determination unit 132c determines the orientation of the cutting blade 58 based on the inclination direction of the second line 156b with respect to the first line 156a.

[0124] Specifically, when the cutting blade 58 is attached to the cutting unit 20a so that the first surface 60a of the protrusion 60 is positioned forward of the second surface 60b in the rotation direction of the cutting blade 58 (see FIG. 5(A)), an edge detection image 154 as shown in FIG. 10(C) is obtained. In the edge detection image 154, the second line 156b is inclined clockwise by a predetermined angle with respect to the first line 156a. In this case, the orientation determination unit 132c determines that the cutting blade 58 is attached in the correct orientation (proper attachment state) and outputs a proper attachment signal to the drive control unit 134.

[0125] On the other hand, if the cutting blade 58 is mistakenly attached to the cutting unit 20a so that the first surface 60a of the protrusion 60 is positioned further rearward in the rotation direction of the cutting blade 58 than the second surface 60b, an edge detection image is obtained that is a left-right inversion of the edge detection image 154 shown in FIG. 10(C). In this edge detection image, the second line 156b is inclined counterclockwise by a predetermined angle with respect to the first line 156a. In this case, the orientation determination unit 132c determines that the cutting blade 58 is attached in the wrong orientation (misattached state) and outputs an incorrect attachment signal to the drive control unit 134.

[0126] As described above, the image processing unit 132b may extract the first straight line 156a and the second straight line 156b corresponding to the first surface 60a and the second surface 60b of the protrusion 60 of the cutting blade 58. In this case, the orientation determination unit 132c determines the orientation of the cutting blade 58 based on the relationship between the inclinations of the first straight line 156a and the second straight line 156b extracted by the image processing unit 132b.

[0127] The determination unit 132 can also determine the orientation of the cutting blade 58 based on the result of comparing the image of the protrusion 60 of the cutting blade 58 with a reference image. That is, the determination unit 132 may determine the orientation of the cutting blade 58 by pattern matching. Hereinafter, other examples of the method for determining the cutting blade will be described with reference to Fig. 6 and Fig. 11(A) to Fig. 11(C).

[0128] First, a reference image acquired in advance is stored in the storage section 136 of the control unit 56. As the reference image, an image of the protrusion 60 acquired by capturing an image of the outer periphery of the cutting blade 58 with the imaging unit 94 when the cutting blade 58 is properly attached is used. FIG. 11(A) is an image diagram showing the reference image 160.

[0129] When determining the mounting orientation of the cutting blade 58, first, the outer periphery of the cutting blade 58 is imaged by the imaging unit 94 to obtain the captured image. As a result, an image of the protrusion 60 of the cutting blade 58 mounted on the cutting units 20a and 20b is obtained.

[0130] 11(B) is an image diagram showing a captured image 162a of the protrusion 60 of the cutting blade 58 in a correctly attached state, and FIG. 11(C) is an image diagram showing a captured image 162b of the protrusion 60 of the cutting blade 58 in an incorrectly attached state. When the imaging unit 94 captures an image of the outer periphery of the cutting blade 58, the captured image 162a or the captured image 162b is acquired depending on the attachment state of the cutting blade 58. Then, the image acquisition unit 132a stores the acquired captured image 162a or the captured image 162b in the storage unit 136.

[0131] Next, the image processing unit 132b reads out the reference image 160 and the captured image 162a or the captured image 162b stored in the storage unit 136, and calculates the similarity between them. Here, if the cutting blade 58 is correctly attached, the captured image 162a is acquired and compared with the reference image 160. As a result, a high similarity is calculated. On the other hand, if the cutting blade 58 is incorrectly attached, the captured image 162b is acquired and compared with the reference image 160. As a result, a low similarity is calculated. Then, the image processing unit 132b outputs the result (similarity) of the comparison between the reference image 160 and the captured image 162a or the captured image 162b to the orientation determination unit 132c.

[0132] The orientation determination unit 132c identifies the attachment orientation of the cutting blade 58 based on the comparison result between the reference image 160 and the captured image 162a or 162b. For example, a similarity threshold is stored in advance in the storage unit 136, and the orientation determination unit 132c compares the similarity input from the image processing unit 132b with the threshold read from the storage unit 136. If the similarity calculated by the image processing unit 132b is equal to or greater than the threshold, the orientation determination unit 132c determines that the cutting blade 58 is correctly attached. On the other hand, if the similarity calculated by the image processing unit 132b is less than the threshold, the orientation determination unit 132c determines that the cutting blade 58 is incorrectly attached.

[0133] As described above, the image processing unit 132b may compare the image of the protrusion 60 of the cutting blade 58 captured by the imaging unit 94 with the reference image. In this case, the orientation determination unit 132c determines the orientation of the cutting blade 58 based on the result of comparing the image of the protrusion 60 with the reference image.

[0134] In addition, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the object of the present invention. [Explanation of symbols]

[0135] 11 Workpiece 13 Tape (dicing tape) 15 frames 2 Cutting equipment 4 Foundation 4a,4b,4c opening 6 Cassette support stand 8 cassettes 10 Chuck table (holding table) 10a Holding surface 12 Moving mechanism 14 Table Cover 16 Dustproof and water-resistant cover 18 Clamp 20a, 20b Cutting unit 22 Support structure 24a,24b Moving mechanism 26 Y-axis guide rail 28a, 28b Y-axis moving plate 30a, 30b Y-axis ball screw 32 Y-axis pulse motor 34a, 34b Z-axis guide rail 36a, 36b Z-axis moving plate 38a, 38b Z-axis ball screw 40a, 40b Z-axis pulse motor 42 Imaging unit 44 Cleaning Unit 46 Spinner Table 46a Holding surface 48 nozzles 50 Cover 52 Display unit (display unit, display device) 54 alarm unit (alarm unit, alarm device) 56 Control unit (control unit, control device) 58 Cutting Blade 58a aperture 60 Protrusions (convex parts, saw blades) 60a 1st face (scooping face) 60b 2nd surface (flank) 60c tip 60d bottom (bottom of blade) 62 Housing 64 spindles 64a aperture 64b screw groove 66 Blade Mount 66a aperture 68 Flange 68a surface 68b Convex part 70 Boss part (support shaft) 70a thread groove 72 Fixing bolt 74 Flange (pressing flange) 74a aperture 76 Fixing nut 78 Blade Cover 80 Main body 82 Slide cover 84 Air Cylinder 86 Connector 88 Connector 90 Connector 92 nozzles 94 Imaging unit 100 Light-emitting unit 102 Case 104 Light source 106 Condenser Lens 108 Mirror 110 Light receiving section 112 Microscope 114 Case 116 Mirror 118,120 convex lens 122 Camera 124 Gas supply line 126 Gas Supply Source 130 Processing section 132 Judgment section 132a Image acquisition unit 132b Image processing unit 132c Orientation determination unit 134 Drive control unit 136 Memory section 140 captured images 142 composite images 142a Maximum point 142b Minimum point 150 captured images 152 composite images 154 Edge Detection Images 154a Edge Line 156a 1st straight line 156b 2nd straight line 160 Reference Images 162a, 162b Captured images

Claims

1. A cutting device for cutting a workpiece, a chuck table that holds the workpiece on a holding surface; a cutting unit having a spindle with a cutting blade attached to a tip end thereof for cutting the workpiece held on the holding surface; an imaging unit attached to the cutting unit for imaging the outer periphery of the cutting blade; a determination unit that determines the orientation of the cutting blade, The cutting blade has a plurality of protrusions on its outer periphery, the protrusions including a first surface for sending out chips generated when the cutting blade cuts the workpiece, and a second surface connected to the first surface; The cutting device is characterized in that the determination unit determines the orientation of the cutting blade attached to the cutting unit based on the image of the protrusion acquired by the imaging unit.

2. The cutting device according to claim 1 , wherein the determining unit determines the orientation of the cutting blade based on the dimensions of the first surface and the second surface of the protrusion imaged by the imaging unit.

3. The cutting device according to claim 1 , wherein the determining unit determines the orientation of the cutting blade based on the inclination of the first surface and the second surface of the protrusion imaged by the imaging unit.

4. The cutting device according to claim 1 , wherein the determining unit determines the orientation of the cutting blade based on a result of comparing the image of the protrusion captured by the imaging unit with a reference image.

Images